Premium
Relative importance between biogeochemical and biogeophysical effects in regulating terrestrial ecosystem‐climate feedback in northern high latitudes
Author(s) -
Zhu Xudong,
Zhuang Qianlai
Publication year - 2016
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1002/2016jd024814
Subject(s) - biogeochemical cycle , environmental science , biogeochemistry , ecosystem , climate change , radiative forcing , forcing (mathematics) , atmospheric sciences , ecology , geology , biology
Warming‐induced changes in structures and functions of northern terrestrial ecosystems (NTEs), including their regulation on terrestrial biogeochemistry and surface energy balance, may exert positive or negative feedback to the climate system. However, the relative importance among these biogeochemical and biogeophysical feedback is not well understood. Here we use a terrestrial ecosystem model to quantify spatially explicit ecosystem‐climate feedback over NTEs (north of 50°N) under four climate change scenarios from 2010 to 2100, including biogeochemical feedback from climate‐induced changes in net CH 4 exchanges (NME) and net CO 2 exchanges (NCE) and biogeophysical feedback from changes in surface energy partitioning associated with snow cover and vegetation biomass dynamics. Our results indicate that (1) biogeochemical and biogeophysical feedback are attributed more to the changes in NME and snow cover dynamics, respectively; (2) net biogeophysical feedback is much larger than net biogeochemical feedback; (3) NTEs will cause a net positive radiative forcing of 0.04–0.26 W m −2 between 2010 and 2100. Our findings support the notion that NTEs will exert positive net climate feedback; however, our estimation of positive net biogeochemical feedback including NME‐ and NCE‐induced effects is contrary to previous studies showing negative net biogeochemical feedback including NCE‐induced effect only. This study highlights the importance of NME‐induced biogeochemical effect in regulating ecosystem‐climate feedback in NTEs and implies that previous studies without considering NME‐induced effect might have underestimated the intensity of total terrestrial feedback to the climate system.